Circuit interrupter



Jan. 12, 1937. H.l J. cRABBs CIRCUIT INTERRUPTER Filed May 26, 1934 3 Sheets-Sheet 1V INVENTOR 'ATTRN Jan. 12, 1937. H. J. cRABB's 2,067,659

CIRCUIT INTERRUPTER Filed May 26'. 1934 5 Sheets-Sheet 3 ATTOR EY Patented Jan. l2, 1937 UNITED STATES CIRCUIT INTERRUPTER Herbert J. Crabbs, Wilkinsburg,

Pa., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa.,

Pennsylvania a corporation of Application May 26, 1934, Serial No. 727,746

20 Claims.

My invention relates to circuit interrupters, and particularly to outdoor disconnecting switch- `es for use with medium and high voltage transmission circuits.

Switches of this type ordinarily comprise a pair of yspaced insulators, a contact means mounted on each of theinsulators, a blade for bridging the l contact means, and a means for actuatingv the blade. It is desirable that the plane of movement of the blade be parallel to the axes of the insulators, this construction yielding a vertical break switch which occupies a minimum of ground space. It is also desirable thatA the insulator columns be subjected to as little cantilever stress as is possible, since all of the economically practicable insulators, while capable of resisting rela.- tively large torsional stresses, fail when subjected to relatively low cantilever stresses.

'Ihese switches'are generally used for disconnecting or sectionalizing portions of a transmission line. Usually they are mounted outdoors and are subjected to very severe weather conditions as a result of ice or sleet formations.

Moreover, in the normal course of events, the switches are operated `very infrequently, thus providing an almost ideal condition for oxide and corrosion formation. The switches must be low in cost due to the large number used; they must becapable of reliable operation under themost adverse conditions without unduly straining the supporting insulators; the contact must include means for vcutting through corrosion during the circuit closing operation so as to `assure good electrical contact; and the switches must be inherently safe so as to prevent injury to the operator or to the protected equipment. f

These requirements are somewhat conflicting, because it is ordinarily very difcultfto secure high contact pressure, with a wiping or corrosion cutting engagement of the contacts during the circuit closing operation, without subjecting either one or both of the insulators to a cantilever stress which is substantially proportional to the contact pressure secured. One method of accomplishing the desired contact pressure and wiping action between the engaging contact surfaces without unduly straining the supporting insulators consists in the rotation of the entire switch blade. 'Ihis arrangement is objectionable in that it has a tendency to freeze up during the winter time and has not proven entirely satisfactory.

Another arrangement used in the past consists in the provision of two longitudinally movable blades, both of which are supported upon one of the insulator columns. A switch of this type is (Cl. 20o-48) disclosed and described cations, Serial Nos. 2,027,900, issued Jan.

in my copending appli- 697,611 now Patent No. 14, 1936 and 697,612, both of which are assigned to the assignee of this invention, rand it is with improving switches of this general type thatthe present invention is particularly concerned.

'I'he principal object of the present invention is to provide an improved high voltage disconnecting switch that shall beinexpensive to manufacture, that shall be'sa'feand reliable in operation, and that shall include means for securing high pressure contact accompanied by a wiping engagement of the cooperating contact surfaces during the circuit closing operation, without unduly straining the supporting insulator columns.

This object of my invention is accomplished through the provision of a switch utilizing a parallel blade construction. One of the blades is adapted to move longitudinally of the other during the circuit closing operation so as to eifect a wiping engagement accompanied by high contact pressure between the cooperating contact surfaces of the blade and the contact. The other blade includes means operable during the circuit closing operation to mechanically engage the outboard insulator column so as to rigidly interconnect both of the insulators, thereby limiting the stress which might be placed on either co1- umn during the operation of the switch, and at the same time providing a structure of considerable strength and rigidity. The interconnecting means in the preferred embodiment of my invention automatically adapts itself to a considerable amount of relative movement of the insulator columns, and thereby assures satisfactory operation of the switch despite any relative movement which might be produced as a result of adverse weather conditions or damage to the switch itself. 40 A further object of my invention is to provide an improved Aform of multiple blade construction partly adaptable for use with disconnecting switches for high voltage circuits, the blade to have sufficient inherent rigidity to prevent undue 45 movement of the contact portion thereof which might result from wind acting upon the long span ordinarily encountered in high voltage switches.

A still further object of my invention is to provide an improved disconnecting switch which 5 shall accomplish the above stated objects and operate satisfactorily despite the vformation of ice and sleet or the like.

These and other objects oi' my invention will be more clearly understood from the following Fig. 2 is a. fragmentary elevational view show-l ing the disconnecting switch illustrated in` Fig. 1 in the partially opened position.

Fig. 3 is a plan view of the disconnecting switch shown in Figs. 1 and 2 in the closed-circuit posi-`v tion.

Fig. 4 is a fragmentary elevational view show.v

ing the disconnecting switch shown in FigsLl to 3 in the open-circuit position. t

, Fig. 5 is a fragmentary plan view of the contact structure of the switch illustrated in Figs.

l to 4 in the partially opened position.

Fig. 6 is a sectional view on the line VI-VI of Fig. 1.

Fig. 7 is a sectional view on the line VII-'VII of Fig. 6. 'e

Fig; 8 is a perspective view of the support element for the lower blade, and

Fig. 9 is a perspective view of the support link for the upper blade.

As shown in the drawings, the preferred emv bodiment of my invention includes a base. lor support member I for the switch, a pair of'stationary insulator columns 3 and 5 which are rigidly mounted upon the support member I through the agency of bolts 1, a contact jaw 9 mounted uponv the upper insulator 3, a pair o! blade members II and I3 mechanically connected to each otherv by a pair of link members I5 at the upper end and a single link member I1 at the lower end, a`

rotatable insulator I9 likewise mounted upon the base I, and actuating means intermediate 'thel` rotatableinsulator I9 `and the blade means.

The two stationary insulator columns land-5l' and the rotatable insulator' column I9 are of the usual high voltage type fandvcomprise a number of ceramic rain shields'cementedtogether with' a cap 23 of conducting materialat the upper end and a supporting member. 25 at the lower end. Each` of the supporting members 25 terminates in a flange 21, which in the case of the two stationary insulators 3 and 5 is directly bolted to the `base I, a suitable spacing washer 29 being provided u for securing the desired positioning of. the insula ,e tor columns. The flange 21 of the insulator col- .y umn I9 is directly bolted to a bearing 3| which. permits the insulator column I9 tov be. rotated toeiect the actuation of the switch.

The yU-shaped contact jaw I9, which shownjy particularly in Figs. 6 and 'lis bolted vto theinsu-V I latbrcap 23 of the upper stationary insulator] by means of suitable bolts 33, and Vcomprises af pair of upstanding side portions 35 which r cast integral therewith. Each of the sid vpo tions 35 is provided with a contact portion 31 A, a guide portion 39. The guide portionsy39 ar disposed at an angle withv respect to. thecontac portions a1 in order to facilitate thel entryorlthe cooperating portionsr of the blade duringr thecir-'-'l cuit closing operation. The contact...portion'31 of the right-hand upstanding member-,35 isina.-r chined in the form of a tooth in order topermit the stationary insulators 3 and 5 to be rigidly interconnected during the circuit closing operation, and the contact portion 31 of the .other side of the jaw is rounded in order to permit the coopei'atingcontect 'portionof the blade to engagethat portion with e wiping action during the operation-of the switch.

A U-shaped support member 4 I which is shown particularly in Figs. 1 and 3, is rigidly affixed to the insulator 'cap of the secondary stationary insulator by means of suitable bolts 43. This U- shaped support member, as will be described in some detail later, is utilized for providing a pivot point for permitting the blade to be swung to the open and to the closed-circuit position during the operation of the switch.

A atplate member 45, also shown in Figs. 1 and 3, ispositioned beneath the U-shaped support member 4I. This plate member 45 is provided'with a suitable opening 41, slightly greater in diameter than the base portion 5l of the actuating crank 49, which is bolted to the cap portion 23 ofthe rotatable insulator I9 by the bolts 55. The opening 41 engages the base portion 5I o! nal and shaft and serves, during the operation to the switch, as a tie forpreventing undue relative movement between the rotatable insulator I9 and the mechanically interconnected stationary insulators. f

the crank arm 49 ina manner similar to a joux'- The lower portion of the plate member 45 is L provided with .an opening (not shown) for en gaging vthe bolt 55 which serves to electrically I Lconnect theV lower:tornantiv s1 of the switch a thereto. Theupper terminal 59 of the'switch is supported upon a suitable .outwardly projecting portion 6I `cast integral with :the.u'shaped iita'-l tionary contact 9.

The rotatable 4insulator kcolumn-.I9 supported rgaged by theswitch operating lever (not shown).

The outer portion of the actuating crank 49 which fissupported uponithe rotatable insulator I9 is provided with a bifuroated portion '61. having the pin 69 intermediate the actuating crank and thetle member 1I.

pair of tubular members II and I3 which are joined together by suitable links so as to form a quadrilateral Aassemblage which is pivotally vsupported at one' oi the corners thereof. 'I'he longi.

tudinal axes of the two blade members are skewed at all times rin order that the bladey assemblage shall possess a maximum of rigidity. This skew-y ing of the blades is shown 'particularly in Figs. 1, 2 and 3 and is of particular value in securing a satisfactory high voltage switch because the long spans (sometimes as much as eighteen i'eet)` which must be bridged by the blade in switches y, fthis type make it imperativethat the blade shall be very rigid.

The lower blade member II comprises a solid copper rod of considerable inherent rigidity,

which is provided with a contact member` 13 at its outer-end' and a bifurcated support member 'I5 (Fig. 3)v at its'inner end. The member 15, as is shown inFlgs. 1 to 3, is adapted to be pivotally supported kupon the U-shaped support' member 4I amxed tothe-lower stationary insulator column-,5 throughV the agency of a pivot pin y11.

This pivot pin 11. also servesv as a. support for the `suiti'tbly-disposed. openings therein for engaging@ l l a v, I. VvThe blade comprises, as mentioned above, a

operating link I 1v which is disposed intermediate the two blade members Il and I3 at their pivoted end.

As is shown particularly in Fig. 8,' both o! the rality 'of teeth formed opposed sides I9 of the biiurcated support mem-v ber 'I5 are provided wi projections 8| Iare adapted to cooperate with suitable projections 83 lforming a part .of the up- Y standing sides of the U-shaped support member 4| in order to limit the upward movement oi the blade during the circuit 'opening operation.

Y The upper blade member. I3 comprises a simiportion for engaging the proper, anda contact oi substantially the same outline-as'thetoothed contact portion 31 of the right'hand sidel oi.' the contact jaw lSi and serve during the circuit closingoperation, as a means for interconnecting the two stationary insulator columns. A plurality oi'- teeth are provided in order that the blade shall becapable of automatically accommodating itself to a considerable amount of rela/tive movement ot thestationary insulators which might result during high winds or other unusual conditions.

The contact member 85 for-.fthe upper blade member I3 is essentially similar to the contact member 13 for the lower blade; except that the contact portion 95 thereof is, machined ilat.'`

During they operationl ofk the switch the upper'v blade I3 moves longitudinally with respect Yto the lower blade andthe cooperating contact surfaces of the contact portion 85 ofl the upper bladeand the left-hand portion-35 or the jaw engage with a wiping action. The contact surface oi' the left-hand portion '31 of the jaw 9, as explained above, is rounded in order to restrict the contact surfaces to a small area. v The tie member II is provided for mechanically interconnecting the actuating crank I9 aixed to the rotatable insulator I9 and -the blade assemblage, a pair of universal joint means 91 and 99 being provided to permit the# switch actuating mechanism to accommodate itself to vthe rather complex movement of the various parts of the blade means. vThe outer ends ofjthe two blade members are mechanically interconnected by the tie links I5 and two pivot pinsIUI as is shown particularly in Figs. 6 and 7. 'I'hese links I5, in

comblnationwith the main "actuating link I1, serve to deine the movement vof the two blade members I I and I3, and during the closing operation of the switch cause the contact portions 93 and 95to move away from eachother in'order to eiect a high pressure engagement between the cooperating contact surfaces and to mechanically other during thecloslngoperation .ci the switch, and since the separation of the contact. s iafaces '31 formed in the sides -oi .theii'aw an outwardly extending projection 8| cast integrallytherewith. These l ing a threadedihole n 'I'he contact member 'I3 for the lower bladeyI I` comprises a cast memberhaving a suitablebody outer fndof theblade 1 portion 93 `haviiigfja-l plu''` therein. -Theseiteeth ,are I "i Flexible shunts ||I and to the position shown in Fig. 2.

member is greater than the separation olA the space througliwhich the contact portions of the blades must pass when moving through the jaw during the operationoi the switch, it is necessary that the contact portions of the blade members be biased towardfeach other, i. e. to a position where the blade can vbe readily moved intoand out oi the contactjaw. The flat leaf spring |03 is particularly desirable. purpose in that it is not readily clogged by ice, and i! ice should be formed about it, it will subject the ice to a tensional stress during the operation of the switch, and thereby cause it to break without undue strain being placed upon the operatingmechanism. 'I'he actuating link II- is provided with a suitable-machined portion |05 hav- |01 therein for permitting one end ofthe spring |03 to bel mechanically connected thereto. and the biiurcated support 'I5 for -the lower blade member is provided with a simif lar machined portion for engaging the other end of .the spring, bolts y |09 being utilized to fasten the ends of the sp g to the two members.

I I3 are provided for electrically interconnecting the two blade members I land I3 and for connecting those members to the capportion 23 of the lower stationary insulator 5, the bolts. I I5 serving toeect the desired e1ectrical connections.

The electrical circuits through the switch is very direct., Beginning with the upper terminal 59, the current and 95l oi' the two blade members |I and I3, .thence vthrough thebody portions of the blade `members the shunts III, to the cap portion 23 of the second stationary insulator i. and `thence through the plate member 45 which is electrically connected to the cap portion of the second stationary insulator to the other terminal 51.

The switchis shown in the closed-circuit position in Figs. l and 3, and it will be noted that the center of the pin 69 which connects the operated crank l4 9 with the tie link 1| has been moved to a position somewhat to the left of the line con- ,latched in the closed-circuit position by virtue of the fact that'the contacting portions 93 and 95 of the two blade members II and I3 have moved awayfrom each other a distance greater thangthe separation of the restricted midportion-||9 (Fig. 'Y

6) of the stationary contact jaw 9.y

for accomplishing this" flows through the stationary contact jaw 9, the cooperating contact portions 93 To open the switch theinsulator I9 rotated in a clockwise direction from the position shownA in Figs. 1 and 3. The ilrst eil'ect of this rotation is to move the pivot pin 69 from the overcenter position tov a position where the rotation of the insulator and the actuating crank 49 moves the link 1I away from the fully-closed position The blade assemblage has not, during this movement, rotated about the main support pin I'I, but the entire eil'ect of the movement of the link 1I has been to move the' upper blade I3 longitudinally,

an axial direction, oi' the lower blade II. The

limits of this longitudinal movement are defined by the link members I5 and II which mechanically interconnect the two blade members, and

the immediate eiiect is to cause the contact' portions 93 and 95 of the blade members to move toward each other a suiiicient distance to permit the blade means to disengage thecontact `law. Further movement of the rotatable insulator will cause the quadrilateral blade assemblagev to rotate Iabout the pivot'pin 'II to the open-circuit position shown in Fig. 4. l

' The iiat leaf spring=Ill3 serves to maintain the blade members against movement toward` thek To close the switchv the insulator I9 is 'rotated in a counter-clockwise direction' from the position shown in Fig. 4. This rotation causes the blade to swing'back into engagement with the jaw, the flat spring |03 maintaining the proper positioning of the blades, and upon further'rotation of the insulator the upper blade member I3 is caused to move longitudinally in an axial direction of the lower blade member II to effect engagement of the cooperating contact surfaces. The toothed portion 93 of the lower blade member I I engages the similarly proportioned contact surfaces 3`I of the right hand side 35 of the jaw 9, and as the circuit closing operation is completed, serves to effect a. rigid interconnecting of the two-stationary insulator columns 3 and` 5. The contact portion 95 of the upper blade member I3 engages the rounded contact portion 31 of the left hand side 35 of the `iaw member with a wiping action which effectively cuts through any corrosion or oxide which may exist between the cooperating contact surfaces.k t

Since the two stationary insulators 3 and 5 are mechanically interconnected during the circuitclosing operation, by virtue of the engagement of the toothed portion 93 of the lower blade member II with the jaw 9, the cantilever stress which results from the longitudinal movement of the blade I3 is divided substantially equally between the two insulator columns. The cantilever stress is also' taken up to a more or less extent through the shaft and journal engagement of the rotatable insulator I9 and the member 45.' The combined result of the mechanical inter-v connecting of this insulator columnis to prevent excessive cantilever stresses on either of the stationary insulator columns or the rotatable insulator column during the operation of the switch. In effect all of the insulator columns are mechanically interconnected, and each aids the others in producing a rigid structure which will operate satisfactorily when subjected to the most adverse operating conditions.

.An arcing horn I2I is aixed to the base portion of the stationary contact jaw 9 and is adapted to cooperate with a suitably `dimensioned arcing horn |23 amxed to the contact portion 93 of the lower blade member II. This arrangement causes the electrical circuit through the switch to be nally interrupted not at the engaging contact portions of the blade and jaw members but at the arcing horns, and permits the switch to be used for interrupting low ampercontact surfaces.

'I'he upward swingable movetions.

acerque age circuits without damage to the engaging kThe skewedrelation of the blade members is maintained at all times during the operation of the switch in order to impart rigidity to the blade assemblage. The link members I5 which interconnect the two blade members II and I3 at.

awayfrom the engaging contact surfaces-' Thls is'done inorder that theresilience of,v the blade members themselves may be used for securing the desired contact pressure between the engaging contact'surfaces during the operation of the switch. f

' It will thus be seen that I have' disclosed an improved high pressure contact disconnecting switch which includes a pair of spaced stationary insulator columns, a blade for bridging the'conducting means aiiixed to the topportion ofveach of the two insulator columns, and a rotatable insulator having means associated therewith for actuating the blade. 'Ihe cooperating contact portions of the blade and the stationary contact are provided with engaging toothed portions which, during the operation of the switch, serve to mechanically interconnect both of the two statheir outer portion are positioned some distance tionary insulator columns in order to prevent" either one of these columns from being subjected to undue cantilever stresses. Moreover. the cooperating interconnecting means areautomatically adjustable in orderto compensate for any relative movementof'the insulator columns which might develop during the operation of the switch.

Further, my improved switch includes an operating mechanism which is so arranged that the movable portions exposed to ice formation move, during the operation of the switch, so as to cause suchr ice as may be formed to be stressed either in tension or in shear, thus practically eliminating any possibility of the switch freezing fast in either the opened or the closed circuit position. When my improved switch is in the closedcircuit position the blade and the -operating mechanism are both securely latched against movement as a result of magnetic stresses, and at the same time the latching means are both entirely releasable 'through the rotation of thesingle rotatable insulator.

. Attention is directed to the fact that the various parts of the switch shown in this embodiment of my invention are all mounted on single insulators. It is well known in the art that the insulator columns for disconnecting switches mayV comprise any number of the single insulators and it is my intention that the word .insulator or insulator column shall include either a single insulator or a plurality of insulators.

While in accordance with the patent statutes I have disclosed the details of a preferred ernbodiment of my invention, it is to be understood that manyof these details are merelyillustrative and that variations in their precise form will not be only possible but necessary in some applica- I desire, therefore, that my invention should be limited only-as set forth in the appended claims and by the prior art.

I claim as my invention:

1. In anelectrical switch, a pair of spacedinsulator columns, conducting means mounted on each of said columns, movable blade means for bridging said conducting means to provide an electrical circuit therebetween, and actuating means for moving said blade means to the open and to the closed-circuit position, said blade means and said conducting means including cooperating means engageable at any one of a plurality of points to rigidly interconnect said insulator columns so as to prevent relative movement therebetween during at least a portion of the circuit-closing operation, and said actuating, means moving the switch into iinal closed-circuit position after said insulator columns are rigidly interconnected.

2. In an electrical switch, a pair of spaced insulator columns, conducting means mounted on each of said columns, movable blade means for bridging said conducting means `to provide an electrical circuit therebetween, and actuating means for moving said blade means to the open and to the closed-circuit position, said blade means and said conducting means including cooperating means operable to rigidly interconnect said insulator columns so as to prevent relative movement therebetween during at least a portion of the circuit-closing operation, said interconnecting means comprising toothed members which engage to effect the mechanical interconnecting of said insulator columns and which automatically accommodate themselves to a. considerable amount of relative movement of said insulating columns without subjecting said columns to substantial stress during the operation of said switch.

3. In an electrical switch, a pair o f spaced insulator columns, conducting means mounted on each of said columns, movable blade members for bridging said conducting means to open and to close the electrical circuit therebetween, means for supporting said blade means for swingable movement, and actuating means for moving said blade means to the open and to the closed-circuit position, said blade means and said conducting means being provided with cooperating means operable to cause said insulator columns to be rigidly interconnected so as to prevent relative movement therebetween during` at least the final portion of the circuit-closing operation, said cooperating means including members which are readily movable into and out oi engagement with each other to eiect said rigid interconnection at any one of a plurality of points at which said cooperating means engage when said blade means is swung from one position to the other but which prevent relative movement of said insulating columns after the engagement of said cooperating means, and said actuating means moving the switch into nal closed-circuit position after said insulator columns are rigidly interconnected.

4. In an electrical switch, a pair of spaced insulator columns, conducting means mounted on each of said columns, movable blade means for bridging said Aconducting means to open and to close the electrical circuit therebetween, means for supporting said blade means for swingable movement, and actuating means for moving said blade means to the open and to the closed-circuit position, said blade means and said conducting means being provided with cooperating means operable to cause said insulator columns to be rigidly interconnected so as to prevent relative movement therebetween during at least a portion ofthe circuit closing operation, said cooperating means including toothed members at least one of which is provided with a plurality of teeth, which are readily movable into and out of engagement with each other when said blade means is swung from one position to theother but which prevent feature of said engaging members causing said interconnecting means to automatically accommodate itself to a considerable amount of relative movement of said insulating columns without subjecting said columns to substantial cantilever stress"during the interconnecting operation.

5. In an electrical switch, a pair of spaced, insulator columns, a contact means supported upon one ofsaid columns, a blade means, means for supporting said blade means upon the other of said columns for swingable movement into and out of engagement with said contact means to close andto open the electrical circuit through said switch, and actuating means for moving said blade means, said blade means including means adapted tocooperate with means forming a part of said contact means when said blade means is being moved to the closed-circuit position to rigidly interconnect said insulator columns with any one of a plurality of dierent distances between the ends thereof, and said actuating means forcing said contact means and blade means into final engagement after said insulator columns are rigidly interconnected. Y

6. In an electrical switch, a pair of spaced. stationary insulator columns. a contact means supportedupon one of said columns, a blade means, means for supporting said blade means upon the other of said columns for swingable movement into and out of engagement with said contact means to close and to open the electrical circuit through said switch, and actuating means for said blade means,'said blade means and said contact means having cooperating toothed portions which engage when said blade means is swung into the closed circuit position to rigidly interconnect said insulator columns so as to pre vent substantial relative movement therebetween, the toothed feature of said cooperating portions causing said interconnecting means to automatically accommodate itself to considerable relative movement of said insulating columns without subjecting said columns to substantial stress during the operation of said switch.

7. In an electrical switch, a pair of s paced insulator columns, conducting means supported on each of said columns, movable blade means for bridging said conducting means to provide an .electrical circuit therebetween, saidblade means and said conducting means having cooperating contact portions, and actuating means for moving said blade means to the open and to the closedcircuit position, said blade means comprising a pair of blade members at least one of which is movable longitudinally with respect to the other during the circuit-closing operation to cause the final intimate engagement between the cooperating contact portions of said blade means and said conducting means, said blade means and said conducting means being provided with cooperating means which mechanically interconnect said insulator columns at any one of a plurality of points at which said cooperating means happen to engage during the circuit-closing operation in order to prevent relative displacement of the said columns when said blade member is moved longitudinally with respect to the said other blade member.

8. In an electrical switch, a pair of spaced, insulator columns, conducting means supported on each ofsaid'columns, movable blade means for bridging said conducting means to provide an electrical circuit therebetween, said blade means and said conducting means having cooperating contact portions, and actuating means for movand said conducting-meansf saidblade" means andi' eidg-...provided z with Y y elta, mechanically. ins. terconnect said' insulator columns'during at least a portion ofthe ,circuitlclosin'g loperationin order' cause ari-intimate engagement betweenvthe cof operating contact portions otisaid lblade means toothed members hich` s to prevent relative displacement vof 'the ,saidcol umns when said blade member isfmovedtlongitudinally with respect tothe said jotherlblade member, the toothed feature of saldi#co'operating.'v portions causing said interconnecting ymeans to automatically accommodate itselfto considerable relative movement of said insulating columns without subjecting saidV columns to substantial` stress'during the operation of :said switch.`

9..In an electrical switch, a paire( spaced, insulator columns, a contact means supported upon one of said columns, a blade means, vmeans for supporting said` kbladev means uponjthe other oi' said columns for swingable movement intoand vout of e/ngagementwithsaid contact means to close and to open theelectrical` circuit through saidv switch, andactuating means for said blade means, said blade means comprising a pair of blade members at least one of which is movable longitudinally with respect to the other during the final part of the circuit closing operation to cause high pressure engagement' between the cooperating contact portions of said blade means and said contact means, said blade means and said contact means being provided with coop.

erating means which mechanically interconnect said insulator columns prior' to said iinal circuit closing operation in order `to prevent `relative displacement of the saidcolumns when said blade member is moved longitudinally with respect to the said other blade member, and said coop-y erating means being engageable to interconnect said insulator columns with any one of a plurality of different distancesbetween therends thereof carrying said contact means and said blade means. e y

l0. In an electrical switch, a pair of spaced,

stationary insulator columns, a contact meansA supported upon one of said columns. a blademeans, means for supporting said blade means upon the'other of said columns for swingable movement into and out of engagement with said contact means to close and to open the electrical circuit through said switch, and actuating means for said blade means, said'blade means comprising a. pair` of `blade members at least one of which is movable longitudinally with respect to the other during the circuit-closingoperation. to cause an intimate engagement between the 'cooperating contact portions of said blade means. and said contact means, said cooperating'contact portions including engaging toothed members,; at. least one of which is provided with'a plurality of'tcethfl, v whichl serve to mechanically interconnect "said t. insulator columns during atleast a portion oi?,.

lthe circuit-closing operation relative movement of said during the operation of said switch, the multiplelv ically accommodate itself to a considerable amount oi relative movement of saidlnsulating columns without subjecting said columnsto aubwhen said switch is in the closed-circuit said blade structure and in order to prevent; insulating columns-f 6a means toy automat- *in orderto increase one of said columns, a blade means pivotally supported on the otherv of said columns, for swing- ,able movement into and out of engagement with said. contact means, and' actuating means for *saidl blade means, the engaging contact, portions of said blade means and said contact means including cooperating-toothed members which serve to vrigidly interconnect said insulating columns position, and which rare so arranged that they automatically accommodate themselves to a considerable amount of relative movement of said insulator columns without subjecting those columns to substantial cantilever stress during the interconnecting operation.

l2. In an electric switch, a pair of spaced vstationary insulator columns, a contact means -su'p'- I ported upon one of-'said columns,'a blade means,

and actuating means for moving said blade 2 means to open and to close said switch', said blade means comprising a pair of blade members each of which has a contact portion for engaging cooperating contact portions forniing a part of said' contact means, said blade members being joined together by a pair of link members so as to form a quadrilateral assemblage, said assemblage being pivotally supported at one of its corners t0 permit both of said blade members to be swung into and out of engagement with said contact` means and to permit one of said blade members to be moved longitudinallyof the other, and a ilat leaf spring, mechanically connected at one of its ends to one of said blade members and at the other of its ends to one of said link members, for biasing said assemblage to a predetermined position, said spring being looped about one of Vthe corners of said quadrilateral assemblage.-

13. In 'an electric switch, a contact means. al

movable blade structure, support means for saidv blade structure, and actuating means for moving y said blade structure into and out of engagement with said contact means to operate said switch,r said blade structure comprising a pair of blade members which are mechanically'interconnected Aat both ends thereof, and thelongitudinal axes of said blade members being skewed with respect to each other in all positions of the switch in order to .increasethe inherent rigidity of said blade structure;v f e .l 14. In an'felectricswitch, a contact means, a movable blade structure, support means for said .blade structure.; and actuating means for moving said blade `structure into and out 'of engagement with said contact means to operate said switch,

Said contact means having cooperating contact portions, said. blade structure comprising 4a pair of mechanically in- `terconnectedblade members, which are movable as a unit intoy and out of engagement with said contact means, and'at least oneof 'which is mov- .ablejlongitudinally with res'pect'to the other dur- -ingthe circuit-closing operation to cause an intimate engagement between. thecooperating 'conct means, one oisaid blade members having a y 'iiredplvotnd the longitudinal axes of said blade v tooth feature of said engaging contactvportil'mv I.

i causing said interconnecting 415.1111 an electric switch, a 'contact means. a

tact portions of said blade structure and said con- Y finovable blade structure. support meansror said 75 blade structure, and actuating means for moving said blade structure into and out of engagement with said contact means to operate said switch,

, said blade structure .and said contact means havsemblage, which assemblage is movable as a unit into and out of engagement with said contact means, and at least one of said blade members being movable longitudinally with respect to the other during the circuit closing operation to cause an intimate engagement between the cooperating contact portions of said blade structure and said contact means, the longitudinal axes of said blade members being skewed with respect to each other in all positions of the switch in order to increase the inherent rigidity of said blade structure.

16. In an electric switch, a pair of spaced insulator columns, a contact means supported upon one of said columns, a blade means supported on the other of said columns for swingable movement into and out of engagement with said contact means, actuating means for moving said blade means, said blade means comprising a pair of blade members which are mechanically connected to each other at least lwhen said switch is in the closed vcircuit position to form a generally quadrilateral assemblage, eachV of said blade members having a contact portion adapted to engage said contact means, one of said blade members being movable only about the axis of support of said blade means and the other of said blade members being movable longitudinally with respect to said rst mentioned blade member, during each closing operation of said switch, and means actuable in response to said longitudinal movement to eilect an intimate engagement between the cooperating contact portions of said blade member and said contact means, the contact portions of said rst mentioned blade member and said contact means including cooperating toothed members which serve to mechanically interconnect said insulator columns during at least a portion of the circuit closing operation of said switch, in order to prevent relative movement of said insulating columns when said last mentioned blade member is,v moved longitudinally with respect to said rst mentioned blade member.

17. In an electric switch, a pair of spaced insulator columns, a contact means supported upon one of said columns, a blade means supported upon `the other of said columns for swingable movement into and out of engagement with said contact jaw, actuating means for said blade means, said blade means comprising a pair of blade membersA which yare mechanically connected to each other by suitable spaced linkages so as to form a quadrilateral assemblage, one of said blade members being supported for movement only about the axis of support of said blade means and the other of said Vblade members being movable longitudinally with respect to the ilrst mentioned blade member during each closing operation of said switch to actuate saidlinkages and thereby effect an intimate engagement between the cooperating contact portions of said blade members and said contact means, the engaging contact portions of said rst mentioned blade member and said contact means comprising cooperating toothed members which serve to mechanically interconnect said insulator columns during at least a portion of the circuit closing operation in order to prevent relative movement of said insulating columns when said last mentioned blade member is moved longitudinally with respect to said first mentioned blade member of said switch, the toothed feature of said engaging contact portions being so arranged that said interconnecting means automatically accommodates itself to a considerable amount of relative movement of said insulating columns without subjecting those columns to substantial cantilever stress during the operation of said switch.

18. In an electric switch, a contact, and a blade means supported for swingable movement about a fixed pivot into and out of engagement therewith, the engaging portions of said contact and said blade means including cooperating toothed members which engage when said switch is in the closed circuit position, and at least one of said cooperating members being provided with a plurality of teeth in order that said members shall engage in 'any one of a plurality of positions.

19. In an electric switch, a pair of spaced insulator columns. a contact supported upon one column, and a blade means supported upon the other column for swingable movement about a xed pivot into and out of engagement with said contact, the engaging portions oi' said contact and said blade means including cooperating toothed members which engage when said switch is in the closed circuit position to rigidly interconnect said columns, and at least one of said cooperating members being provided with a plurality of teeth in order that said members shall engage in any one of a plurality of positions.

20. In an electric switch, a pair of spaced insulator columns, a contact supported upon one of said columns, a blade means supported on the other of said columns for swingable movement about a xed pivot into and out of engagement with said contact means, actuating means for said blade means, said blade means comprising a pair of blade members each ol which has a contact portion adapted to engage said contact means, one of said blade members being movable only about the xed axis of support of said blade means and the other of said blade members being movable longitudinally with respect to said rst Vmentioned blade member during each closing operation of said switch, and `means. actuable in response to said longitudinal movement toel'ect bers which engage whensaidswitch is in the closed circuit position to rigidly interconnect said insulator-columns, Vand at least one of said cooperating 1members -being provided with a plurality ofteeth in order that said members shall engage and interconnect said columns in anyone of a plurality of positions.

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